中文摘要：

载波移相SPWM调制方法存在开关损耗大、直流电压利用率低等不足,且不易于和矢量控制、直接转矩控制等高性能的控制系统相结合.SVPWM调制方法因具有直流电压利用率高、动态性能好、易于数字化实现等优点在两电平控制领域得到了广泛的应用,但直接应用于多电平逆变系统由于开关状态过多导致不易实现.采用一种新型的延时叠加SVPWM调制方法,在不增加算法复杂性的前提下,把SVPWM调制方法应用到级联H桥高压变频器系统中,通过Matlab仿真并在实验室380V三单元级联变频器设计项目中对其进行测试,仿真与实验结果有力地证明了这种调制方法的的可行性和正确性.

英文摘要：

The carrier phase-shifted SPWM modulation method not only has the disadvantages of large switching loss and the poor utilization rate of DC voltage,but also has the poor dynamic performances.This paper puts forward a new type of delay superposition of SVPWM control strategy based on the sample time-staggered thought of carrier phase-shifted SPWM modulation method.This modulation method regards a multilevel system as a combination of two-level systems,which is simple in controlling and easy to realize.In addition,it is successfully applied to a cascaded H-bridge multilevel-inverter system based on DSP ＋ FPGA.The simulation and experimental results show that this method not only solves the problem that SVPWM modulation method is difficult to apply to a multilevel system because of too many synthesis switch states,but also reaches to a high DC voltage utilization ratio with a simple algorithm and a good dynamic performance.